User Manual

Demand Assignment
System Overview GSI 003
605-0000-450
Draft Issue 1.3dr Date 8/02/00
Page 8 of 8
• Three Combiner Shelf PSUs to provide the interface between the local DC power
source and the equipment of the AS4000 CT Rack. The shelf contains two circuit
breakers, to give protection by using two independent DC supplies, and three PSUs
that supply a nominal 13.5V DC. The input to the PSU can be in the nominal range
of −24V to −60V.
• Power for the RF cards is provided from a PSU contained in the combiner monitor
card and a redundant monitor card containing only a PSU is used to provide power
backup in the event of failure of the monitor card PSU.
• The RF Combiner Shelf also contains an alarm extension unit which receives alarm
information from the AS4000 equipment, analyses it and then informs the local suite
alarm system to which certain alarms are extended. Depending on the severity of the
condition, the alarm extension unit recognises either a Prompt alarm (immediate
attention required) or a Deferred alarm (action can be delayed).
9.4. CT Expansion Rack Shelves:
The Expansion Rack provides two modem shelves as described in 9.3.1. DC supplies
and alarms are fed to the rack via a Alarm and Breaker Panel
1
A B
2
A B
3
A B
4
A B
5
A B
SHELF PROTECTION
Figure 14 Alarm and Breaker Panel